How to Add New Items to List in WinForms DomainUpDownExt

18 Nov 20181 minute to read

To add new items that the user enters at runtime after the user has pressed the Enter key, you need to handle the KeyDown event.

C#

private void domainUpDownExt1_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
{
    // Add new items when user presses the Enter key.
    if (e.KeyCode == Keys.Enter)
    {
        if (!domainUpDownExt1.Items.Contains(domainUpDownExt1.Text))
        {
            domainUpDownExt1.Items.Add(domainUpDownExt1.Text);
        }
    }
}

VB.NET

Private Sub domainUpDownExt1_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs)

    ' Add new items when user presses the Enter key.
    If e.KeyCode = Keys.Enter Then
        If Not domainUpDownExt1.Items.Contains(domainUpDownExt1.Text) Then
            domainUpDownExt1.Items.Add(domainUpDownExt1.Text)
        End If
    End If
End Sub